The overall aim of this project is to gain greater understanding of mechanisms underlying the control of secretion of thyroid stimulating antibody (TSAb) that is the cause of hyperthyroidism of Graves disease. Such increased understanding will clearly bene the clinical management of patients with this disorder and, moreover, will enhance understanding of the pathogenesis of other autoimmune disorders including Type I diabetes mellitus and myasthenia gravis. The methods to be employed include the development of hybridomas that will secrete monoclonal antibodies to substances related to these interests. Specifically, we shall develop TSAb-secreting hybridomas with patients peripheral lymphocytes and both human myelomas and EB virus-transformed human peripheral lymphocytes; mouse hybridomas will be developed to try to produce TSAb experimentally. Patients peripheral blood lymphocytes will also be used in vitro to study factors (particularly the role of T cells) controlling the secretion of TSAb by these cells. As part of that project, the antigen corresponding to TSAb, namely the receptor for thyrotropin, will be purified and used to stimulate the lymphocytes to secrete TSAb. Attempts will be made to establish a TSAb-secreting cell line by transforming with EB virus appropriate peripheral blood lymphocytes obtained by fluorescein-activated cell sorting. A major aim will be to develop a simple yet precise assay for clinical studies. The techniques to be further explored by us include the use of monolayer cultures (primary, of human thyroid; established line (FRTL cells) of rat thyroid) for stimulation-type assays and several designs of TBI (TSH-binding inhibition) procedures. For the latter guinea pig fat cell membranes or solubilized human thyroid membranes show promise for specificity though possibly too poor in sensitivity. Perhaps with a combination of stimulation type and TBI-type assays, attempts will be made to develop a prognostic index that will permit early identification of patients requiring ablative therapy (surgery or radioiodine) for their hyperthyroidism. Finally, detailed longitudinal studies will be carried out in pregnant thyrotoxic women to assess the influence of pregnancy on this autoimmune disease. The scientific disciplines involved are thus endocrinology, immunology and clinical medicine.